Abstract

Background

Macular thickening (MT) without clinically recognized macular edema has been described
in anterior uveitis (AU). Although fellow-eyes of patients have been used as controls
in several studies, little is known about macular thickness in these eyes. We studied
the rate and extent of MT in both AU-affected and quiescent fellow-eyes of phakic
AU patients with good visual acuity (VA). We also assessed macular thickness related
to HLA-B27 presence and to recurrence, since these issues have been almost unexplored
by previous optical coherence tomography (OCT) studies.

Methods

Patients with AU were prospectively included and macular thickness was measured with
OCT initially and on follow up. Macular thickness in patients’ affected eyes (n = 30)
as well as in their quiet fellow-eyes (n = 28) was compared with eyes of age- and
gender matched controls. Inter-ocular differences in macular thickness between AU
affected eyes and their fellow-eyes were assessed in patients (n = 28), also in a
subgroup with visual acuity ≥ 0.8 (n = 23) by one-sample Student’s t-tests. Inter-ocular
differences were also assessed related to HLA-B27 presence and related to the status
of current AU episode (initial or relapse).

Results

Subclinical MT is present in both quiet fellow-eyes and AU-affected eyes of patients.
MT was found in most cases of AU, even in phakic eyes with good VA. There was a larger
increase in macular thickness in HLA-B27-positive than in HLA-B27-negative patients.
No differences in macular thickness were found between patients with their first AU
episode and patients with recurrent episodes.

Conclusions

MT probably reflects systemic immune-mediated response to the inflammatory disorder
in AU, and it is possible that HLA-B27-related factors are involved in the pathogenesis
of AU. These observations are in line with and extend the current understanding of
the mechanisms behind MT in AU.